Hydroxylamine, hydrochloride sulfate

A mixture of 150 grams of 1-(3, 4 -dimethoxyphenyl)-2-propanone and 70 grams of hydroxylamine hydrochloride in 125 cc of water is stirred while a solution of 51.3 grams of sodium carbonate in 150 cc of water is added over the course of 15 minutes, and while maintaining the reaction mixture at 30°-40°C. The reaction mixture is stirred for an additional two and one-half hour period at room temperature, and is then diluted with an equal volume of water and extracted three times with 300 cc portions of ether. The combined ether extracts are washed with water, dried over anhydrous magnesium sulfate, and the... 

N sodium hydroxide solution (5 ml) is added to a stirred suspension of S-methyllsothiosemi-carbazide hydroiodide (2.33 g) and hydroxylamine hydrochloride (0.70 g) In water (6 ml) and stirred for 48 hours. The solution is evaporated In vacuo to provide 1 -amino-3-hydroxy-guanidine. One-third of the residue is dissolved in 16 ml of ethanol and 2,6-dichlorobenzalde-hyde (0.6 g) Is added to this solution. The reaction mixture is then stirred for 48 hours. The solution is then evaporated in vacuo and the residue dissolved in ether (30 ml) and in hydrochloric acid (30 ml). The aqueous phase is rendered alkaline with 2 N sodium carbonate solution and extracted with ether. The ether layer is dried with sodium sulfate and evaporated. 

Hydroxylamine, hydrochloride, 55,40 Hydroxylamine sulfate, 58, 32, 36 Hydroxylamine-O-sulfonic acid, 58, 32, 34, 36... 

The base was being prepared by distilling a mixture of hydroxylamine hydrochloride and sodium hydroxide in methanol under reduced pressure, and a violent explosion occurred towards the end of distillation [1], probably owing to an increase in pressure above 53 mbar. It explodes when heated under atmospheric pressure [2], Traces of hydroxylamine remaining after reaction with acetonitrile to form acetamide oxime caused an explosion during evaporation of solvent. Traces can be removed by treatment with diacetyl monoxime and ammoniacal nickel sulfate, forming nickel dimethylglyoxime [3], An account of an extremely violent explosion towards the end of vacuum distillation had been published previously [4], Anhydrous hydroxylamine is usually stored at 10°C to prevent internal oxidation-reduction reactions which occur at ambient temperature [5], See other REDOX REACTIONS... 

Hydroxylamine hydrochloride is highly irritating to the skin, eyes, and mucous membranes and has caused contact dermatitis in workers exposed for 2-60 days. Hydroxylamine itself is only moderately irritating to the skin. Hydroxylamine sulfate on the skin of rabbits was irritating at levels as low as a 10-mg dose. It is considered to be a potential skin sensitizer. 

TNB, Methanol, Potassium iodide, Hydrochloric acid, Sodium bisulfite, Methylene chloride, Magnesium sulfate Hydroxylamine hydrochloride, Glyoxal, Sodium carbonate, Ethanol, Chlorine, Chloroform, Methanol, Ethylenediamine, Ethylene glycol, Sodium hydroxide, Trifluoroacetic anhydride, Nitric acid, Acetone... 

In many applications, relatively large quantities of anhydrous sodium sulfate can be added to the sample, prior to extraction by organic solvents, in order to enhance the partitioning process (333-336, 341, 342, 354, 365, 370). In some instances, such as in the analysis of clorsulon in bovine liver and milk, addition of hydroxylamine hydrochloride is often recommended prior to extraction (329, 360). The use of this agent is to prevent interactions between the analyte and endogenous aldehydes that lead to loss of recovery. 

Prepare a supply of a dilute solution of sodium silicate (density, 1.06) by dilution of commercial water glass and pour it into an equal volume of 1-normal acetic acid. Add enough copper sulfate to make the solution 0.05-normal with respect to the copper sulfate. Fill several tubes half full of the solution and set them aside until a firm gel is obtained. To each test tube add a layer several centimeters deep of a 1 per cent solution of hydroxylamine hydrochloride. In several weeks, the tetrahedral crystals of copper may be observed, best in bright sunlight. 

The hydroxylamine hydrochloride used was the crude material prepared as described in Org. Syn. 3, 61. Preliminary experiments showed that this reagent must be present in considerable excess. Equally good results were obtained by using a solution of crude hydroxylamine sulfate which also contained sodium sulfate and ammonium sulfate with a little excess sulfuric acid. The hydroxylamine content was determined in this solution by titration with potassium permanganate solution. When this crude solution is used, the addition of sodium sulfate is not always necessary. 

Of these methods, that of Sandmeyer 2 using aniline, chloral hydrate, and hydroxylamine salts, seemed most promising and has been studied in detail. The present method differs from that described by Sandmeyer in the use of hydroxylamine hydrochloride instead of a crude solution of hydroxylamine sulfate, and in the use of sodium sulfate to salt out the isonitroso compound. 

To a solution of sodium acetate in acetic acid was added hydroxylamine hydrochloride, and methanol was added until solution resulted. This solution was added to a solution of 2-hydroxymethylene-4,4,17a-trimethyl-androsta-2,5-dien-17p-ol-3-one in absolute methanol, and the combined solution was refluxed for 40 min on a steam bath. The reaction mixture was concentrated, the residue extracted with ethyl acetate, and the ethyl acetate extracts were washed with ethyl acetate, and the ethyl acetate extracts were washed with 5% hydrochloric acid, dried over anhydrous sodium sulfate and concentrated whereupon there separated solid material. 

A 90 x 6 cm column was packed with 2 kg of granular Amberlite IRA-410 resin in the chloride form (a vinylpyridine/divinylbenzene copolymer quaternized with dimethyl sulfate and converted to chloride) and washed with 3 kg of a 10% aqueous solution of sodium cyanate. This changed the resin from the chloride to the cyanate form. Sodium chloride and excess sodium cyanate were then washed from the column with distilled water until the effluent failed to give a white precipitate with silver nitrate. The reaction of equation (2) was conducted by elutriating the column with a solution of 105 grams (1.5 mols) of hydroxylamine hydrochloride in 400 ml water at about 15°C. 

To a solution of isopropyl ester of 6-formyl-5-methoxycarbonyl-2-methyl-4-(3-nitrophenyl)-l,4-dihydropyridine- 3-carboxylic acid (4.5 g) in acetic acid (35 ml) were added hydroxylamine hydrochloride (0.97 g) and sodium acetate (1.43 g), and the mixture was stirred at ambient temperature for 2.5 hours. After acetic anhydride (4.14 g) was added to this reaction mixture, the mixture was stirred at ambient temperature for 1.5 hours and at 95-100°C for additional 4 hours. The acetic acid and the excess of acetic anhydride were removed in vacuum, followed by adding water to the residue and it was neutralized with a saturated aqueous solution of sodium bicarbonate. This aqueous suspension was extracted twice with ethyl acetate, and the combined extract was washed with water, dried over anhydrous magnesium sulfate and evaporated to dryness under reduced pressure to give a reddish-brown oil (4.88 g), which was chromatographed over silica gel (150 g) with a mixture of... 

Palomo75 report that various aromatic aldehydes can be converted to nitriles in 94-97% yield by refluxing the aromatic aldehyde, hydroxylamine hydrochloride, and magnesium sulfate in toluene or xylene, with p-toluencsulfonic acid as catalyst for 1.5 to 3 hr. The microwave-assisted process may prove better for aliphatic aldehydes and may be made even more attractive if the above process conditions could be refined to reduce or eliminate NMP—for instance, if both aldehyde and nitrile form a homogeneous liquid at the reaction temperature. 

C. Preparation of the reducing agent. One hundred and twenty-five grams (0.5 mole) of cupric sulfate pentahydrate is dissolved in 500 ml. of water contained in a 3-1. three-necked flask equipped with a mechanical stirrer, and then 210 ml. of concentrated ammonium hydroxide (sp. gr. 0.90) is added with stirring. The solution is cooled to 10°. A solution of 40 g. (0.575 mole) of hydroxylamine hydrochloride in 140 ml. of water is prepared and also cooled to 10°. To the hydroxylamine hydrochloride solution there is added 95 ml. of 6 A sodium hydroxide solution, and if not entirely clear, it is filtered by suction. This hydroxylamine solution is immediately added to the ammoniacal cupric sulfate solution with stirring. Reduction occurs at once with the evolution of nitrogen, and the solution becomes pale blue. If this solution is not used at once, it should be protected from the air. 

Hydroxylamine Hydrochloride Solution Dissolve 20 g of hydroxylamine hydrochloride in sufficient water to make about 65 mL, transfer the solution into a separator, add a few drops of thymol blue TS, then add ammonium hydroxide until the solution assumes a yellow color. Add 10 mL of a 1 25 solution of sodium diethyldithiocarbamate, mix, and allow to stand for 5 min. Extract the solution with successive 10- to 15-mL portions of chloroform until a 5-mL test portion of the chloroform extract does not assume a yellow color when shaken with cupric sulfate TS. Add 2.7 N hydrochloric acid until the extracted solution is pink, adding 1 or 2 drops more of thymol blue TS if necessary, then dilute to 100 mL with water, and mix. 

The method developed by Sandmeyer is the oldest and the most frequently used for the synthesis of isatin. It consists in the reaction of aniline with chloral hydrate and hydroxylamine hydrochloride in aqueous sodium sulfate to form an isonitrosoacetanilide, which after isolation, when treated with concentrated sulfuric acid, furnishes isatin in >75% overall yield17. The method applies well to anilines with electron-withdrawing substituents, such as 2-fluoroaniline18, and to some heterocyclic amines, such as 2-aminophenoxathine19 (Scheme 1). 

Preparation, A solution of copper(n) sulfate pentahydrate in concentrated aqueous ammonia is stirred under nitrogen, cooled, and treated with hydroxylamine hydrochloride to effect reduction. Then a solution of phenylacetylene in ethanol is... 

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